1. Field of the Invention
This invention generally relates to welding systems, and more specifically relates to welding systems for implantable devices.
2. Description of Related Art
In modern manufacturing systems it is often desirable to have the ability to manufacture different types of devices in the same manufacturing line. By reducing the need for additional manufacturing equipment and lines, the overall efficiency of the manufacturing system is improved. Improving the efficiency of the system provides the ability to produce devices at lower costs, an important factor in today's competitive world economy.
One type of manufacturing system commonly used in a wide variety of applications are laser welding systems. Laser welding systems use lasers to provide automated welding on production devices. In an automated laser welding system, devices are brought into a welding chamber and held by a tool. A laser is then used to perform welding on the device. The whole process is typically controlled by a computer to make the welding as automated as possible.
When attempting to manufacture different devices with different operational requirements, the welding environment can be a significant issue. For example, it is generally desirable to weld devices in an inert, weld-friendly environment. This improves the quality of the weld and the finished device. Unfortunately, the gases that make up the weld-friendly environment may not provide the operational requirements for some types of devices. These devices require a different type of gas be inside the device before it is welded shut.
An example of this problem is found in the manufacturing of implantable cardiac devices. Implantable cardiac devices include a wide range of different types of medical devices. For example, implantable pulse generators (IPGs) are a type of cardiac device that is used to steady the rhythm of a beating heart. This type of device, often referred to as a Bradycardia device or a pacemaker, do not require operational high voltages. Another type of implantable cardiac device are implantable cardiac defibulators (ICDs). This type of device, often referred to as a Tachycardia device, can be used to provide a defibulator shock to the heart when a heart problem is sensed. These ICD devices have significantly greater voltage requirements than the IPG devices.
To provide the voltage needed by the ICD, these devices are typically formed with a high dielectric gas, such as a nitrogen mixture, inside the device. Thus, they must be welded shut or sealed in a nitrogen gas mixture. In contrast, IPG devices do not require the high voltage and thus are typically welded shut with an inert welding gas, such as an argon mixture, inside the device. These differences in gas requirements have led in the past to these devices being manufactured in different processing lines. This lowers the efficiency of the system, and results in overall higher costs to consumers.
Thus, what is needed is an improved welding system that provides for different welding environments and thus allows different types of devices to be formed on a manufacturing line.